Generac Holdings Inc., commonly referred to as Generac, is an American manufacturer of backup power generation products for residential, light commercial, and industrial markets. Generac's power systems range in output from 800 watts to 9 megawatts and are available through independent dealers, retailers, and wholesalers. Generac has headquarters in Waukesha, Wisconsin, and manufacturing facilities in Berlin, Oshkosh, Jefferson, Eagle, and Whitewater, all in Wisconsin. Wikipedia